The present invention relates to a fluid flow insert for directing flowing fluid from a curved passage in a front engine cover toward a cylinder block of the engine.
A front cover is typically mounted on the front end of an internal combustion engine, and may include various engine accessories mounted thereon, such as an oil pump, an air compressor, a heat exchanger, an oil filter, a coolant pump, a thermostat, etc. Various configurations of front covers are shown, for example, in U.S. Pat. Nos. 6,247,436, 5,704,329 and 5,477,817.
In those front covers which incorporate an oil pump or coolant pump, fluid flow channels are formed within the front cover to carry the pumped fluid to the adjacent cylinder block. In the interest of improved packaging, overall engine size has continuously decreased. Accordingly, the size of the front cover has decreased. Specifically, the cover has gotten thinner. In transverse-mounted engines, the cover has gotten approximately 50% thinner. This is potentially problematic because a pump, such as a coolant pump, in a front cover would pump the coolant along a front cover fluid flow channel which is transverse to the engine block. This flowing fluid must then be redirected orthogonally toward the engine block to cool the engine block. In such a thin front cover, the orthogonal turn in the fluid flow channel must be very sharp, which may induce turbulence, and therefore loss of efficiency in the cooling system.
Accordingly, there is a need to improve the efficiency of pumped fluid traveling from a front cover to an engine cylinder block.
The present invention provides a plastic insert which is positioned within the curved portion of a front cover fluid passage to improve flow conditions. The plastic insert includes a plurality of curved fluid flow vanes to direct flowing fluid through the curved portion in a manner to improve laminarity of the flow and to reduce fluid losses.
More specifically, the invention provides an engine assembly for a vehicle, including an engine crankshaft protruding from a front end of a cylinder block of the engine and a front cover secured to the front end of the engine. A pump is positioned within the front cover and operatively connected with the engine crankshaft. A fluid passage is formed by the front cover for receiving pumped fluid from the pump and directing the fluid into the cylinder block. The fluid passage has an exit port with a curved portion of the passage positioned closely adjacent the exit port. A plastic insert is positioned within the curved portion and within the exit port. The plastic insert has a plurality of curved fluid flow vanes to direct flowing fluid through the curved portion in a manner to improve laminarity of flow in the curved portion and in the exit port to reduce fluid flow losses.
Preferably, the plastic insert includes a rim which is trapped between the exit port and the cylinder block of the engine. The plastic insert is preferably injection molded from a plastic material having high heat characteristics, and the front cover is preferably a cast aluminum component which is bolted to the cylinder block.
Another aspect of the invention provides a method of manufacturing a vehicle engine assembly including the steps of:
a) providing a crankshaft protruding from a front end of an engine;
b) providing a front cover over the front end of the engine, the front cover including a pump therein operatively driven by the crankshaft for pumping fluid through a fluid passage formed within the front cover, the fluid passage having an exit port facing a cylinder block of the engine and having a curved portion of the passage closely adjacent the exit port; and
c) trapping a rim of a plastic insert between the cylinder block and the exit port, the plastic insert having a plurality of curved fluid flow vanes positioned in the curved portion of the fluid passage to direct flowing fluid through the curved portion in a manner to improve laminarity of flow in the curved portion and in the exit port to reduce fluid flow losses.
Accordingly, an object of the invention is to provide an improved front cover assembly in which fluid flow losses are reduced for fluids being directed into an adjacent cylinder block.
The above object and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.